package android.objects;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Region;
import android.graphics.RegionIterator;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.PictureDrawable;
import android.view.View;

public class SampleView extends View {
	private final Paint mPaint = new Paint();
	private final Rect mRect1 = new Rect();
	private final Rect mRect2 = new Rect();

	public SampleView(Context context) {
		super(context);
		setFocusable(true);

		mPaint.setAntiAlias(true);
		mPaint.setTextSize(16);
		mPaint.setTextAlign(Paint.Align.CENTER);

		mRect1.set(10, 10, 100, 80);
		mRect2.set(50, 50, 130, 110);
	}

	private void drawOriginalRects(Canvas canvas, int alpha) {
		mPaint.setStyle(Paint.Style.STROKE);
		mPaint.setColor(Color.RED);
		mPaint.setAlpha(alpha);
		drawCentered(canvas, mRect1, mPaint);
		mPaint.setColor(Color.BLUE);
		mPaint.setAlpha(alpha);
		drawCentered(canvas, mRect2, mPaint);

		// restore style
		mPaint.setStyle(Paint.Style.FILL);
	}

	private void drawRgn(Canvas canvas, int color, String str, Region.Op op) {
		if (str != null) {
			mPaint.setColor(Color.BLACK);
			canvas.drawText(str, 80, 24, mPaint);
		}

		Region rgn = new Region();
		rgn.set(mRect1);
		rgn.op(mRect2, op);

		mPaint.setColor(color);
		RegionIterator iter = new RegionIterator(rgn);
		Rect r = new Rect();

		canvas.translate(0, 30);
		mPaint.setColor(color);
		while (iter.next(r)) {
			canvas.drawRect(r, mPaint);
		}
		drawOriginalRects(canvas, 0x80);
	}

	private static void drawCentered(Canvas c, Rect r, Paint p) {
		float inset = p.getStrokeWidth() * 0.5f;
		if (inset == 0) { // catch hairlines
			inset = 0.5f;
		}
		c.drawRect(r.left + inset, r.top + inset, r.right - inset, r.bottom
				- inset, p);
	}

	@Override
	protected void onDraw(Canvas canvas) {
		canvas.drawColor(Color.GRAY);

		canvas.save();
		canvas.translate(80, 5);
		drawOriginalRects(canvas, 0xFF);
		canvas.restore();

		mPaint.setStyle(Paint.Style.FILL);

		canvas.save();
		canvas.translate(0, 140);
		drawRgn(canvas, Color.RED, "Union", Region.Op.UNION);
		canvas.restore();

		canvas.save();
		canvas.translate(0, 280);
		drawRgn(canvas, Color.BLUE, "Xor", Region.Op.XOR);
		canvas.restore();

		canvas.save();
		canvas.translate(160, 140);
		drawRgn(canvas, Color.GREEN, "Difference", Region.Op.DIFFERENCE);
		canvas.restore();

		canvas.save();
		canvas.translate(160, 280);
		drawRgn(canvas, Color.WHITE, "Intersect", Region.Op.INTERSECT);
		canvas.restore();
	}
}